Fish Dissection: Male or Female?

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You may recall that in my post, Fish Suicide, I had discussed the importance of teaching my son or daughter how to find answers instead of giving them. I asked my daughter, "Is it male or female?"  She answered "I don't know daddy tell me."  I used that opportunity to allow my daughter to "Google" it and find the answer.  After much sifting we did find pictures of the Tilapia genitalia and therefore had the resources needed for our dissection of our little tilapia.

Females have two openings (not including the anus) and males have one opening

As a former high school biology teacher I have dissected almost everything under the sun from starfish to cow eyeballs. This allows me access to borrow the tools I need and the experience to dissect the fish.

The whole set-up.  Ipad for anatomy, dissecting scope, gloves, dissecting tray, and tools

One of the things I took for granted was animal preservation.  In high school, we receive our animals for dissection in preservatives so as to keep all the anatomical features intact.  When our fish was found dead next to our outside tank, we should have dissected it right then.  Instead, I put it into the freezer and found out that this is definitely not the way to preserve.  My specialty in college was entomology (the study of insects) and our easy way to preserve for pinning the insects was to put them into the freezer.  This is not the way to preserve our fish. Therefore when we finally got around to opening our fish it was nothing but mush.  No swim bladder, intestines, heart, liver, or stomach. Bummer. We will need another sacrifice in the future to continue our internal anatomy lesson.

We did go through the external anatomy which included all the dorsal, caudal, anal, pelvic, and pectorial fins.  We also looked at the eyes, mouth, operculum (gill cover), lateral line and then looked at the scales and gills under the microscope.

Of course, we started with the question, male or female?  After looking at the comparisons of our picture reference and the actual anatomy of our little fish my daughter determined that the fish was male. 

My daughter looking at a picture of male and female Tilapia

My daughter determining the sex of the fish.

Cut number one.

I think her face expression says it all.  Remember the inside was gushy mushy. 

Budding young scientist with ipad.

Our adventure continues......